


Careful Creature

by weicheidarling



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/M, Fantasizing, Female My Unit | Byleth, Masturbation, Pining, Sylvain really be out here fam, dimitri has a crush
Language: English
Status: Completed
Published: 2019-12-26
Updated: 2019-12-26
Packaged: 2021-02-26 10:28:07
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,251
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21967825
Author URL: https://archiveofourown.org/users/weicheidarling/pseuds/weicheidarling
Summary: Dimitri is pent up and is cursed with the room next to Sylvain's. He really can't help his mind going to his professor in situations like this.
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth
Comments: 3
Kudos: 141





	Careful Creature

**Author's Note:**

> I didn't really proofread this and like. Wrote the first half of it in my notes on my phone but. Idk man I really cant be held responsible for what I come up with when it comes to Dimitri. 
> 
> Title pulled from Ocean Eyes by Billie Eilish

The walls in Garreg Mach were thin. Entirely too thin. Thin enough that Dimitri could hear Felix dropping his sheathed sword and its accompanying belt in a heap at his door before flopping into bed after a night of training. Thin enough that he could hear Sylvain trying to shush a pretty girl’s giggling and babbling as he pulled her into his room. If she was this loud, how Sylvain had managed to sneak her past Ingrid, let alone the rest of the nobles’ rooms, Dimitri couldn’t fathom but, he was too drained from the day’s events to bother with scolding them. 

Dimitri supposed he could at least be grateful that just this once, he hadn’t fallen asleep yet before Sylvain got started. He wasn’t quite sure how, but it was preferable over waking to the lilting creaks of Sylvain’s oak bed and some unfamiliar girl’s breathy praises. _Would this one praise the goddess or Sylvain himself tonight?_ Dimitri wondered somewhat bitterly. 

The cold walls did offer at least enough of a barrier that Dimitri couldn’t make out the exact words Sylvain was using to coax the girl into undress, but Dimitri could imagine it was something uncivilized by how she laughed before being cut off with Sylvain's bemused shushing. Sometimes he thought he might like to be a fly on the wall to observe Sylvain’s silver tongue in action, to understand how exactly he could make so many girls shower him with attention, but Dimitri supposed he was better off not knowing. 

He really had no use for the knowledge anyway. He hadn’t the time nor inclination to use it after all. (Let alone duty. Dimitri desperately didn’t want to start himself on another anxiety-induced downward spiral over how unworthy he was of his inheritance tonight.) And who would he use it on? It wasn’t that Dimitri considered himself frigid. He just- had a lot more important things to worry about than romance or. Carnal pleasures. 

Scrubbing a hand over his face, Dimitri rolls onto his back restlessly. He hadn’t been sleeping lately. Too many late nights in the library. Maybe that's why he was pondering this while Sylvain pushed tonight’s companion against his desk, jostling some books to falling on the floor and thumping the furniture against these damned too-thin walls. 

Dimitri had always thought it a blessing that Sylvain’s bed was against his room's far wall, and his barely used desk was what shared a wall with Dimitri’s bed. How naïve of him. 

He felt frozen stiff when the girl’s teasing laugh melts into a weak, filthy noise that sends a shiver down Dimitri’s spine. He knew girls could make noises like that, but. He hadn't known he could get goosebumps from it while feeling this hot.

Some part of Dimitri thinks he should cover his ears, or maybe find a way to make his presence known- to embarrass the girl into silence. He does neither for some reason. Instead, he finds himself pushing up to his elbows, then leaning over to touch the cool wood of the wall. 

Her laugh had been unfamiliar, but that noise. The breathy words murmured around Sylvain’s skin, if Dimitri closed his eyes and concentrated, it sounded somewhat like the professor’s. She never laughed, Dimitri supposed, which was why he hadn’t placed it sooner. But now, as she gasped and hummed, it was all Dimitri could think about. 

He found himself pushed to his knees, drawing his blankets around his shoulders as if that could shield him from judgmental eyes, though he knew he was alone. He let his forehead rest on the wall, trying to hang onto her noises through the wall, even as Sylvain carried her away toward the bed. Unconsciously, or maybe not, Dimitri knotted his hand in his shirt to keep a bridle on whatever ugly thing was rearing itself in the pit of his gut.

He hated how good it felt, that graceless, unrefined little thing.   
He could hear Sylvain’s smooth timbre, no doubt saying something velvety sweet as honey and wondered if the professor liked lines like that. No, Dimitri decided, he could picture her impassive expression at some cheesy line. Maybe even a little disappointed, brows turning up in the middle. Dimitri was getting better at reading her subtle expressions and filing away the new ones he discovered in his mind's eye. He wasn’t quite sure if she was growing more expressive with time, or he was becoming more fluent in reading her. Dimitri liked her soft, barely-there smiles the best, but he wondered what she might look like lips parting around a weak, wet moan. He couldn’t seem to imagine her face contorting the way this girl’s must be.

Dimitri pushed down hard between his legs as if that could keep his hunger at bay. He didn't want to just imagine it; he wanted to see it. The professor laid out on a bed, panting and keening. Dimitri grit his teeth. Denying himself hurt, but he knew the resulting shame would hurt more. 

If he was smart, he would stop listening, stop tempting himself. Stop pretending he was some lackadaisical casanova with sweet words to throw around, and his professor was an easy-to-impress girl hungry for a noble’s attention. 

More than smart, he was tired and desperate for release. His ears felt hot, his head stuffy like he had a cold. His hands were sweating like mad, and the slight chill of the uninsulated wall was doing little to clear his mind. 

Sylvain’s voice mixed in with the girl’s intermittently as he teases her like he was playing with his food. Somehow that wasn't the turnoff that it should be, hearing his friend’s voice while he was imagining laying his professor out on his bed, climbing between her legs and - Perhaps he could ask for an oral lesson? That was clever, wasn’t it? It sounded like something Sylvain would say. Would she hate that? 

Having given up, Dimitri released his shirt and cups himself, chewing his lip now to remain composed, lest he let out a noise of his own. Even in the dark of his room, he could see the embarrassing dark stain on his pants where his erection jut against the fabric. Air pushed forth from his nose loud enough that, for a moment, that sound was all that fills his ears before he composed himself. Goddess, if the sound of him was enough to drown out their voices, could they hear his impossibly heavy breathing through the wall? Was he too paranoid? 

Among the lusty moans from the girl, Dimitri could hear the rhythmic knocking from the posts of the bed hitting against the wall, and with it, Dimitri found himself rocking into his palm, sinking his teeth into his bottom lip hard, daring only to let out a tense hum at the minuscule amount of pleasure it gave him. 

He had never given himself the charity of imagining how he might take the professor if she were to let him. It seemed a fool’s errand to dream of her beneath him, but he’d already started and couldn't bring it in him to stop. 

For a moment, he thought of her seated on top of him, teaching him how it was done with deft rolls of her hips. Dimitri imagined she had experience before coming to the monastery, so it seemed only fitting that she tutor the novice Dimitri in lessons of the flesh. She’d look so lovely, he dreamed, her hands planted on his chest to keep her balance, her breasts rising with the draw of her breath, hair drawn over one shoulder. 

But no, he decided as he finally gave himself leave to shimmy his pants down his thighs, what he wanted most was her beneath him, legs drawn up around his sides, hair a chaotic halo draped over his pillow. Maybe she would demurely try to cover her chest with her hands, until Dimitri gently untangled her arms, drawing her hands for her around his shoulders to coax her into holding him. He slicked his thumb through his precome and shuddered, thinking of his professor so shy and out of sorts. 

He didn’t quite hold himself in his hand yet, choosing instead to push down the foreskin and continue coating the head with ample precum. He was terribly pent up, he supposed. Too many nights forgoing sleep or self-gratification in favor of pouring over old kingdom ledgers. He thought, maybe without a salve to keep the clumsy friction of his hand at bay, this was a mistake, but with this much precum he could roll the foreskin back over the sensitive underside of the head, now blush pink and straining, and that offered its own kind of pleasure. It was teasing and not as satisfying as completely fisting himself, but he was in no hurry, savoring the stimulation the voices through the wall offered and whatever his mind came up with.

Dimitri had no idea what to expect beneath the professor's clothes. Sometimes she seemed entirely divorced from what was human, and it was a little terrifying, but in those rare moments, where their wrists had brushed or her chest pressed against his shoulder as she directed him in combat training, Dimitri knew she was soft. Tender, even. 

He’d felt the softness of her breasts once as he pinned her in a training maneuver, just before she expertly upended his balance and threw him off, and found himself remembering it, and fantasized over how supple they would feel cupped in his hands. How sweet they would taste in his mouth, tongue laving over her nipple, the comfort and warmth in them. Her fingers would find purchase in his hair, petting and caressing around his ear. Dimitri’s brow ached in its furrow, and he all but whimpered at the thought, hips rolling into his hand minutely. 

God, he felt hot down to his chest, sticky beneath his shirt but somehow afraid to push away the blankets that he hid in. The corners of his mouth pulled down, and his brow furrowed, hanging on to the rising chants through the wall and fabricating a simulation of the professor opening her legs to invite him in. He would give up his whole kingdom to know what it felt like inside her at that moment, no doubt hot and wet and perfect for him. 

It was with a combination of small movements from his hips and his hand gliding in the not-nearly-ample-enough precum he’d spread that Dimitri found his pleasure, moving to the beat of moans from some woman he had not even seen the face of and his imagination desperately painting the picture of his beloved professor beneath him.

He savored the idea of sinking into her tight heat and bowing into her shoulder as she adjusted to him. Her soothing voice, ever gentle and reassuring, coaxing him through with fingers drawing along his shoulders and sinking into his hips. 

It was far from the first time Dimitri had found himself comparing himself with the professor. Through his lineage, he had inherited impossible strength, and Dimitri had yet to discover what exactly had gifted the professor some inhuman qualities of her own, but where Dimitri struggled to move through the academy without leaving a wake of rubble, the professor had an amazing air of serenity. He couldn’t help thinking of it now, her gentleness working tension from his shoulders, thumbs smoothing over his cheeks as she kissed him, fingers lacing together, and perhaps she, with her infinite tolerance, would not flinch at his proclivity for holding things a bit too tight. 

The voices on the other side of the wall are racing quickly toward a crescendo, and Dimitri desperately combs his hair from his eyes, wanting to savor this feeling, to prolong that building pleasure. Still, as Sylvain was drawing more desperate noises from the girl in his bed, Dimitri couldn’t help wonder if that might be how his professor would sound, how satisfying it would be to sheath himself deep and release his seed inside her, the two of them finding their climax together. 

It was that thought that sends him over the edge, jetting onto the damn wall that was to blame for this whole mess. His voice cuts off with a crack, swallowing a moan before it can really leave his throat. There were a few tense pulsations of tingling pleasure, but before the stars had cleared from his eyes, the shame was already crawling his neck, settling like the cold sweat soaking his shirt. The fervid bliss was over far too soon, not nearly as much of a relief as Dimitri could have hoped for, and more than anything, he only felt that heavy guilt that always came after and the taut curl of his toes. 

Sylvain’s girl was all but screaming now, and he was trying to muffle the noise beneath his hand, but it hardly registered over Dimitri furiously scrubbing at the mess he’d made of the wall, trying not to think about Byleth just beneath Sylvain’s room. He wondered if she was also kept up by his late-night hobby but doubted her mind went to the same place that Dimitri's had. No, he doubted she saw him as anything more than one of her dear students, and that only made the guilt settle in more heavily. He found his head resting against the wall again, knocking slightly against the wood and groaned to himself.


End file.
